Can you come up with novel ways to mitigate, prevent, or eliminate coking – ‘coke’ is the building up of solid carbon – on fired heater tubes’ internal surfaces?
The Seeker encourages submissions of improved or novel techniques of elimination of coke buildup through on-line or offline cleaning, reduction of coke buildup during operation, or surface treatments/coatings to prevent or reduce coke buildup. These innovative solutions will improve refining processes by improving efficiency and reducing downtime.
In this Challenge, the Seeker encourages intuitive and theoretically-supported ideas and concepts which have not been demonstrated in the past and are reasonably practical to implement in real life: however, if you can submit improved products or services that have been used with evidence of great effect in the field, your submission will be prioritized.
This is a Prize Challenge which requires a written proposal to be submitted and there will be a guaranteed award for at least one submitted solution. By submitting a proposal, the Solver grants the Seeker the right to use any information included in their proposal.
For decades and across many industries, carbon buildup in fired heaters during hydrocarbon heating services interrupts and slows down production – often at considerable cost to the operator and decreased efficiency. In the fired heater tubes used to heat up hydrocarbon feedstocks for refining purposes, the breaking of hydrocarbons results in solid carbon (or coke) buildup inside of these tubes – a process known as “coking”.
The size of the buildup of coke and how often it takes to build up again depends on various factors, including the type of feedstock, temperature used, and operation severity. Coking of these tubes is an ongoing problem in many refinery processes of this type. Not only does it reduce the efficiency of the process but the coke buildup eventually raises temperatures of the tube surfaces close to acceptable ranges with the heater tubes then needing to be cleaned, either through cleaning the heater offline or by using online cleaning (which is less effective).
Taking facilities offline to clean or running at lower loads results in a real dollar value in the millions. Finding better ways to mitigate coking buildup in these facilities will have a massive impact on both efficiency and financial savings across many sectors.
Please find attached a graphic, designed to show conceptual conditions for a fired heater apparatus, for use by Solvers with example temperatures, width examples, and overall structure. This is representative of some fired heaters, not all, and should be used to guide but not completely instruct your solutions.
Solvers are asked to provide their mitigating or preventative solutions to improve current processes or explore novel areas of removing coking. Submissions to this Challenge should reduce the speed of coking and make de-coking easier (in order to improve efficiency and reduce downtime) either through improved cleaning practices, effective coatings, improvements to the pigs used, or other innovative solutions.
Solvers are asked to keep in mind that each type of mitigating solution listed above have their own drawbacks. Offline pigging requires downtime, on-line steam cleaning requires either downtime or lower loads, anti-foulants may affect product quality due to breakdown of applied chemicals, different coatings may not be able to sustain pigging due to their thickness, and online pigging would require redesign of the rubber “pigs” used, etc.
For instance, an online pigging solution while the heater is in operation would be of great interest to the Seeker – however the metal temperature during online pigging could range between 1000F – 1300F, too hot for currently-used pig devices.
Solutions and submissions to this Challenge must take into account the Seeker’s desire to continue running their operations within current operating limits. For your information, here are some general statistics and details about the fired heater use by the Seeker organization:
- Applicability for Coker, Vacuum, and Crude Heaters primarily. Coker heaters in this case will benefit the most and will find faster adoption.
- Timelines: Fired heaters are taken offline at different intervals depending on their loads.
- As a broad example, within a 6 month period of use for a fired heater, ~ 2 days might be spent on the use of on-line steam to remove coke from interior tubes.
- Within a year and a half’s use of a heater with a higher capacity, ~ 10 days might be used on decoking (offline).
- Pigging (offline) takes place over a minimum of 10 days, where the heater must be shut down, cooled, cleaned, pigging is done, and then heater started up again.
- Factors affecting speed and amount of buildup: Operation severity and coke buildup depend on the temperature of the hydrocarbon feedstock when inside the tubes, temperature of the feedstock at the inner surface of the tubes, process conditions, and type of feed.
Your submission to this Challenge should improve the current systems used or provide novel approaches by reducing downtime, increasing the efficiency of cleaning processes, eliminating or reducing coking deposits, or by offering other operational improvement.
THINGS TO AVOID
The Seeker is aware that different hydrocarbon feedstocks have different characteristics in terms of coking propensity. However, the Seeker will not be interested in submissions that suggest replacing the hydrocarbon feed.
Lowering temperatures for online pigging or other cleaning is also not of interest in this Challenge, meaning any online solution must be able to withstand temperatures up to 1300F. However, a lower temperature solution is acceptable if there are no alternate high temperature solutions proposed.
Designs for heater improvements that change the overall size of the heater are also not of interest in this Challenge.